Perovskite-based solar cell using graphene as conductive transparent electrode

Abstract

The present invention relates to a perovskite-based solar cell using graphene as a material for a transparent conductive electrode. The perovskite-based solar cell achieves a maximum conversion efficiency of ≥17% through an appropriate combination of energy bands of a graphene electrode, a hole transport layer, a perovskite, an electron transport layer, and a metal electrode.

1 . A perovskite-based solar cell comprising a graphene layer as a transparent conductive electrode. 
     
     
         2 . The solar cell according to  claim 1 , wherein the transparent conductive electrode is a transparent front electrode. 
     
     
         3 . The solar cell according to  claim 1 , wherein the solar cell has a structure in which a transparent anode composed of the graphene layer, a hole transport layer, a perovskite layer, an electron transport layer, and a cathode are laminated in this order on a substrate. 
     
     
         4 . The solar cell according to  claim 1 , wherein the solar cell has a structure in which a transparent cathode composed of the graphene layer, an electron transport layer, a perovskite layer, a hole electron transport layer, and an anode are laminated in this order on a substrate. 
     
     
         5 . The solar cell according to  claim 3 , further comprises a metal oxide layer deposited on the transparent anode or cathode composed of the graphene layer. 
     
     
         6 . The solar cell according to  claim 5 , wherein the metal oxide layer comprises at least one metal oxide selected from the group consisting of MoO 3 , NiO, CoO, and TiO 2 . 
     
     
         7 . The solar cell according to  claim 5 , wherein the metal oxide layer has a thickness of about 0.5 nm to about 6 nm. 
     
     
         8 . The solar cell according to  claim 1 , wherein the perovskite is prepared using a lead halide adduct. 
     
     
         9 . The solar cell according to  claim 8 , wherein the lead halide adduct is a compound represented by Formula 1:
   A.PbY 2 .Q  (1)
   wherein A is an organic or inorganic halide, Y is F − , Cl − , Br −  or I −  as a halogen ion, and Q is a Lewis base comprising a functional group containing an atom with an unshared pair of electrons as an electron pair donor, the FT-IR peak of the functional group in the compound of Formula 1 being red-shifted by 1 to 10 cm −1  relative to that in a compound represented by Formula 2:
   PbY 2 .Q  (2)
 
   wherein Y and Q are as defined in Formula 1.   
     
     
         10 . The solar cell according to  claim 9 , wherein A in Formula 1 is CH 3 NH 3 I, CH(NH 2 ) 2 I or CsI. 
     
     
         11 . The solar cell according to  claim 9 , wherein the perovskite is prepared by heating and drying the adduct to remove the Lewis base from the adduct. 
     
     
         12 . The solar cell according to  claim 4 , further comprises a metal oxide layer deposited on the transparent anode or cathode composed of the graphene layer.